Method of printing sized paper



1,509,872 FiCE. I

search Room WALLACE J. MURRAY, or nos'ron, MASSACHUSETTS, Assrcuon, BY MESNE ASSIGN- MENTS, T0 TODD PROTECTOGRAPE. COMPANY, INCL, or ROCHESTER, NEW YORK,

A CORPORATION OF NEW YORK.

METHOD or PRINTING srzEi) PAPER.

No Drawing. Application filed June 9,

ToaZZ whom itmag concern: i

Be it known that I, WALLACE J. MURRAY, a citizen of the United States, residing at Boston, in the county of Suffolk and btate of Massachusetts, have invented certain new and useful Improvements in Methods of Printing Sized Paper; and I do hereby declare the following-tube a full, clear, and exact description of the invention, such as will enable .others skilled in the art to which it appertains to make and use the same. 1

- printed.

Repeated attempts have been made to devise a method of printing sized paper which would preclude. the possibility of a subsequent erasure of the printing either by mechanical or chemical means. Such a method has been more particularly sought in printing checks and similar instruments. All previous methods, however, have been subject to certain inherent disadvantages which were 'sufliciently great to defeat the object sought for, namely the production.

of printed or written matter which could not be removed by any known method. The

disadvantages of previous methods may be briefly classified under two headings, the use of inks employing insoluble chemicalresistant coloring matter which is deposited upon the surface of the paper or fabric in such a manner that it may be subs uently erased by mechanical methods and t e use ofsoluble coloring matter which may peneof the paper or fabric but is capable of eing removed by other chemicals. 7

I have discovered that it is possible to initially impregnate sized paper such as is a used for checks and to thereafter employ an ink which will react with the material in the paper to form insoluble coloring matter distributed throughout the body of the paper according to any desired form of predetermined design. The coloring matter so formed cannot be removed by mechanical erasure without destroying the body of the paper and by a suitable selection of materials a fast color may be formed which 3 cannot be removed by chemical means. In

'trate the paper to a varying degree.

1921. Serial No. 476,310. addition have discovered that the ink used in printing or writing upon the paper can base permits the printing to be accomplished with metal type, plates, or with a pen, as desired, in either case the ink penetrating the body of the paper to substantially its entire depth without spreading sufliciently to impair the legibility of the printing or writing. Ordinary printing inks have an oil vehicle in which is suspended insoluble pigments. In printing the pigment is deposited on the surface, while the vehicle maypeney new process takes advantage of this property of oil to penetrate a sized paper, and

in ,my new inks the materials are dissolved rather than suspended in the vehicle. In this way I can carry into the body of the paper reagents which react with materials initially contained in the paper, precipitating insoluble coloredypigments throughout the body of the paper.

As one illustration of my new method of printing sized paper, an azo color can be produced within the body of the paper by first treating the paper with anitrite such as sodium nitrite, or other bodies capable of yielding free nitrous acid, and then printing the prepared paper with an ink consisting of a solution of a primary amine and a developer, such as a phenol, in a fatty acid or other Vehicle capable of penetrating a sized paper and containing in addition a free acid. -A.s an'example a glyceride containing a free fatty acid or other acid may be employed. The. acid in the ink vehicle liberates nitrous acid from the nitrite or other substance capable of yielding nitrous acid in the paper, which in-turn diazotizes the primary amine dissolved in the ink vehicle, this diazotized amine reacting or coupling with the developer to precipitate the insoluble azo color in the body of the paper. The azo color may be made faster by mordanting, that is, treatment with metallic salts or other means familiar to the art of textile dyeing. Such further agents may be included in the. paper, in the ink, or may be used in an after-treatment. It is possible by this method to produce a large number of colors. For example, if

the paper is initially treated with sodium nitrite and is then printed with an ink consisting of beta-naphthol and dianisidine dissolved in oleic acid, dianisidine blue is produced in the body of the paper by the resulting reactions. Owing to the red color of the oleic acid the combination of the dia-nisidine blue therewith may produce a purple or brown in the paper.

It should b understood by those skilled in the art that the oil solvent is intended to embrace fatty acids, glycerides, hydrocarbon and other vehicles capable of penetrating a sized paper, and in addition of liberating an acid from the nitrite with which the paper is impregnated. With the exception of fatty acids the vehicle is in itself incapable of liberating nitrous acid from nitrites and in all other cases an acid must be included among the reagents dis solved in the oil vehicle.

I claim: I

1. A method of makin permanent records on sized paper which pregnating the paper with a reagent capable of yielding nitrous acid and applying to the surface of the paper an ink capable of penetrating the sized paper and reacting with the reagent to liberate nitrous acid and precipitate a pigment within the body of the paper.

2. A method for making permanent records, on sized paper, which consists in initially impregnating the paper with a reconsists in im agent capable of yielding nitrous "acid, and applying to the surface of the paper an ink consisting of a solution of an amine and a developer in an oil capable of penetrating the paper, and liberating nitrous acid from the reagent contained in the paper.

3. A method for making permanent records on sized paper, which consists in impregnating the paper with a nitrite, and applying to the surface of the paper an ink consisting of a solution of a primary amine and a developer in a fatty acid.

4. A method for making permanent records on sized paper, which consists in impregnating the paper with a nitrite, and subsequently applying to the surfiice of the paper an ink consisting of a solution of a primary amine and. a phenol in a fatty acid.

5. A method of printingsized paper,

which consists in initially impregnating the paper with anitrite, drying the paper, and thereafter applying to the surface of the paper an ink'consisting of a solution of a primary amine and a phenol in oleic acid.

6. A method of printing sized paper, which consists in impregnating the paper with sodium nit rite, drying the paper, applying to the surface of the paper an ink consisting of a solution of dianisidine and beta-naphtliol in oleic acid.

7. A sized paper impregnated with a nitrite.

' WALLACE J. MURRAY. 

